The Käppelijoch is a small Gothic chapel on the Mittlere Brücke that was once both a religious site on the bridge, and the scene of public punishments.
Built in the late 14th century as a wooden bridge chapel, the Käppelijoch was replaced by a stone chapel in the 15th century. The wayside chapel offered passing travellers the opportunity for brief devotions, but offenders were also executed by drowning there until 1634.
When the Mittlere Brücke was rebuilt (1903 to 1905), the original Käppelijoch was replaced by a faithful replica.
The relief over the entrance to the chapel shows Bishop Heinrich von Thun, who built Basel’s first bridge across the Rhine, with two angels at his side.